no damage, just try both ways, see which one sounds better to you...

some do it to get upfront bass, but sub is sometimes softer

some prefer harder bass, but then sub sound comes from the back

so is also important to have strong midbass to help the sub bass

have to make it suit to your car first maa, that one more important... not putting in living room like home audio

its actually true, but it doesnt hurt the sub. ive been playing with polarity for years, even with mids & tweets also, and my sifu somore maybe 30 years already doing this..

when we put the sub in a box, the sound comes from the whole box, not just the sub cone. so 2 ways of connecting, 2 ways the cone will move will give 2 types of sound, so we pick which sounds better lah..

last time got no time alignment, so we played with polarity, can get some delay a bit... even with time correction is also consider playing with polarity but in a different way, thats why lot of SQ ppl dont like time correction..